1. Field of the Invention
The present invention relates generally to a disc drive apparatus. More specifically, the invention relates to a disc drive apparatus including structure for absorbing the vibration of a stationary frame in order to protect reading and/writing mechanism from vibration transmitted from the stationary frame.
2. Description of the Background Art
One of the conventional disc which facilitates a vibration absorbing structure has been disclosed in Japanese Patent First (unexamined) Publication (Tokkai) Showa 60-231966. Such conventional disc drive apparatus has a base plate on which is mounted a pick-up as a reading and/or writing mechanism. The base plate is supported on a stationary frame via a resilient or elastic support which serves for absorbing any vibration transmitted from the stationary frame to the base plate so that the pick-up can be protected from such vibration of the stationary frame. The disclosed apparatus also has a loading mechanism including a disc receptacle opening and a disc feeding mechanism for transferring a disc between a loading position and unloading position. In the disclosure, the disc feeding mechanism comprises a pair of feed rollers. The feeding rollers comprises a stationary roller stationarily supported on the stationary frame and a movable roller mounted on a pivotal arm. The pivotal arm is pivotable between an active position, at which the movable roller is shifted to a position for gripping the disc between the stationary roller so as to feed to the disc to one of a loading or unloading position, and an inactive position to place the movable roller away from the disc so as to permit the disc to be rotatingly driven by means of a known disc drive mechanism. The movable roller is also associated with a driving motor via the gear train to be driven by the driving torque transmitted therethrough when the pivotal arm is placed at the aforementioned active position. The pivotal arm is associated with an actuation mechanism which drives the pivotal arm between the active and inactive positions. The actuation mechanism is designed to be commonly driven by the driving motor which drives the movable roller.
In addition, during the disc loading and unloading operations, it is necessary to lock the base plate, which is oscillably mounted on a stationary frame via vibration damping members, to the stationary member so as to restrict movement of the base plate. For this, a locking lever is provided which locks the base plate onto the stationary frame. The locking lever is mechanically associated with the driving motor to be driven to the locking position, maintained at the locking position during the loading and unloading operation, and released from the locking position after completing the loading or unloading operation.
With the construction set for above, it is the conventional practice to perform the loading and unloading operation in such a way that a plunger is activated in response to insertion of a disc for releasing the pivotal arm from locked condition, where the pivotal arm is locked at a position away from the stationary roller. Simultaneously, by the action of the plunger, the locking lever is operated to the locking position for restricting movement of the base plate relative to the stationary frame. By further insertion of the disc to place the disc between the movable and stationary rollers, the driving motor becomes active to drive the movable roller. After the disc is placed at the loading position and chucked on the turntable, the plunger is turned to an inactive position to operate the locking lever to the unlocking portion to permit the base plate to move relative to the stationary frame.
In order to enable the driving motor to drive both of the movable roller and the pivotal arm commonly, a complex construction of the drive mechanism has had to be provided. Namely, in order to perform disc loading and unloading operation and locking operation at their respective desired timing, operation timing of the respective components of the disc drive apparatus has had to be mechanically controlled. This requires complex configuration of components and additional components. Furthermore, because of complex construction, it is difficult to mechanically adjust the operational timings of respective components.